In most cases, yes. The black streaks commonly seen on asphalt shingles are usually roof algae. After a proper low-pressure roof wash treatment, these stains often improve quickly and continue to rinse away with rain.

Not always. Moss and lichen are different from simple black streaking. Our treatment is designed to kill the organic growth safely, but the remaining dead material may stay attached to the shingles while it dries out and naturally releases over time.

That color change is normal. Moss and lichen often change color after treatment as they die. The remaining growth then breaks down gradually through rain, wind, snow, sun exposure, and normal weathering.

Light growth may release within a few weeks. Heavier moss or lichen can take several months. In severe cases, especially with thick lichen that has bonded tightly to the shingles, full release can take up to a year.

Because aggressive removal can damage asphalt shingles. Moss and lichen can bond tightly to the protective granules on the shingle surface. Scraping, brushing too aggressively, or pressure washing may remove those granules and shorten the life of the roof. A safer approach is to treat the growth and let the roof release it naturally over time.

Sometimes, yes. Black streaks usually improve quickly, but moss and lichen may turn white, yellow, tan, brown, or gray before they release. This is part of the normal treatment process and does not mean the roof was missed.

Yes. Moss and lichen can hold moisture against shingles and attach to the protective surface. Once the growth dies and releases, it may reveal granule loss, discoloration, or wear that was already present underneath.

Most roofs do not need an immediate second treatment. After the roof is treated, moss and lichen may turn white, tan, gray, brown, or yellow as they die. That remaining material can take weeks, months, and sometimes up to a year to naturally release from the shingles through rain, wind, snow, and normal weathering. For that reason, we generally do not recommend a second treatment just because dead moss or lichen is still visible during the first year. We prefer to give the roof time to release the dead growth naturally instead of adding unnecessary cost for the homeowner. A follow up may be recommended sooner only if heavy growth appears to still be alive, if thick moss is blocking drainage, if debris is collecting in gutters or valleys, or if a specific area needs additional attention after the initial treatment. Our goal is to treat the roof safely, not sell repeat treatments before the first treatment has had time to fully work.

Yes. Our roof cleaning process follows the low pressure method recommended by the Asphalt Roofing Manufacturers Association (ARMA) for cleaning asphalt shingle roofs. We do not pressure wash shingles, because high pressure can remove granules and cause premature roof wear.